The Atlanta Cosplay Meetup has been making a ton of progress on our Marines & Xenos group costume. We have finished up build day #6 so let's take a look and see where things are at currently!

We've finished principal construction of the Marine torso armor and are working on finishing it currently. The cardboard masters were coated in fiberglass resin to give them strength, and we are going over them with bondo body filler to smooth them out. After a few more passes they should be smooth enough to use as vacuumforming masters, or to mold and cast in resin and fiberglass mat for strength.

We've also started building the leg armor, using the same method as the torso.

All that is left for the Marine armor is to 3D print the shoulder parts, and the helmet and various attachments. Adam purchased the same WWII helmet used in the film, which will become the base for our helmet that we will make out of cast resin and fiberglass mat.

The Pulse Rifle has been assembled and had a first pass of smoothing and cleanup done on it. The entire gun was 3D printed from a high detail model from the game Aliens: Colonial Marines. Another day or so of work and we'll be ready to mold it in silicone!

Adam Keeton lent a hand helping us lathe a test Grenade out of aluminum. This is only a first iteration, we'll need to make a few adjustments and go back and try again. So far the results are very nice looking though!

Plus, he looks like a natural holding the Pulse Rifle.

The Xeno skull has been started. We built the head using a 3D model from the game Aliens: Colonial Marines and a program called 123D Make. What this program can do is generate a 3D interlocking puzzle, sort of
like the wooden dinosaur skeleton puzzles you got as a kid. We can set
it to be however many vertical and horizontal slices and the program
draws up plans, which we then exported to the laser cutter. 4 hours of
cutting and about 60 pieces later, you get this mess.

Assembly really is a simple as finding the numbered slots and sliding
them together. Once you get the first couple of pieces put together the
assembly is a breeze. We took maybe an hour to put the whole thing
together. Once it was assembled, we coated the whole thing in fiberglass
resin to give it strength, and once that cured we filled all of the
holes with expanding foam.

Once the foam cures, we will rasp all of the excess off and skin it in bondo, and use that for our sculpting base.

Valentin is working on the mechanism for the Xeno tongue. We are 3D
designing and printing a rack and pinion gear under tension from a
rubber band, and "cocked" with a worm gear connected to a motor. The
idea is that the Xeno costumers will have a hidden button to open the
mouth and shoot out the tongue via pressure from the band, and the worm
gear will retract and cock the tongue to be shot out again.

Lastly, I started on the Smartgun for my own Marine costume. Every Colonial Marine group needs a Smartgunner, and I would be lying if I didn't say that Vasquez was a bit of a hero as a kid. The Smartgun and the steadicam arm will be built much the way the rest of the build has been, with several 3D printed parts and laser cut cardboard details. The steadicam arm will have a semi-working interior using custom machined aluminum parts and springs. So far the barrel has been cut and printed, with a few more parts on the way.

That's all for now. Stay tuned for more updates as we get closer to our deadline in May!

The Atlanta Cosplay Meetup is a bi-monthly-ish group of cosplayers, prop builders, and costume makers hosted at Freeside Atlanta. We have been meeting since October 2014 to share ideas and projects.

In November we began discussing an idea about making a group costume - something we could all work on, and eventually wear, together - and how we could make that into a reality. After a lot of debate (and a little help for Rachel who had already made her own Xenomorph costume!) we settled on making a Colonial Marines and Xenos group from the Aliens franchise.

We just recently wrapped up our 3rd group build, so let's recap what we've done so far.

Our first build we focused on planning and various ideas of what we wanted to do and how we wanted to get there. We decided to use Pepakura to laser cut cardboard as the rough master for our Marine's armor, and to 3D print some of the detail parts as well as their various weapons.

Pepakura is a program that takes a 3D object and lays it out into 2D faces. The example I like to use for this is creating a a paper craft cube. You can lay out the 6 faces of a cube on a sheet of paper, cut the lines, score and glue tabs, and at the end you have your cube in the real world.

This concept scales up to infinitely complex objects. Cosplayers have been using Pepakura for over 15 years now to create complex suits of armor and props. What I discovered is that Pepakura can export into a format that Freeside's laser cutter can interpret, which turns hours of cutting material into mere minutes.

For our second build, we began laser cutting parts for the Marine torso, starting with the chest. The parts were exported from Pepakura into the laser cutter's software, which was then cut out of cardboard. By dialing in different settings for "cuts" and "scores", we can complete everything in a single job. After about 20 minutes we had all of the pieces cut out and began assembling!

Assembly consists of using hot glue to glue the seams of the cut together. We glue the edges on the inside of the cardboard armor to make sure it keeps it's shape, but this creates big gaps between parts on the front. This won't be a problem for us, since we will be sculpting details and smoothing out the form later on in the project.

For our most recent build, we started applying fiberglass resin to the chest piece. This is used to strengthen the armor so that we can sculpt on it with bondo body filler. While the chest was curing, we began cutting and assembling the back armor. Adam also started 3D printing the Pulse Rifle, which should be ready to clean up and assemble at the next build day.

Rachel also brought her Xeno costume so we could brainstorm ideas on how to create the next version of that. Kevin, our other Xeno, and Rachel and I decided we will cut the Xeno skull out of cardboard stacks for the rough master, which they will harden and sculpt.

Our next build will see a lot of progress, since we are now at a point where we can have teams of people working on different smaller parts. We will cut out and assemble the leg armor, start bondo sculpting on the chest, and fiberglass and bondo the back. We'll also be working on the Pulse Rifle, and may have some of the other Marine weapons to start 3D printing. Our team of Xenos will work on the cardboard jigsaw puzzle.

On Saturday, we had one of our semi regular facility build-outs. These are great for the space and our members as it lets us focus on working on the space itself as a project to improve and maintain Freeside.

This time we did a lot of cleaning up and tidying after some of the major projects at Freeside! Between the JAM build the past few months and the recent power additions, a lot of organization work was needed.

Demontre and Niels put some more time into the indoor paint booth! Not much left on this project now, all we need is the exhaust fans and the filters and we're ready to paint.

Nathan and Paul painted the new folding chairs for the space.

Karen and Adam helped to tidy up the lumber and plastics consumables. Now we can get to scrap lumber and laserable plastics easier!

Everyone pitched in to clean up the center of the workshop and open that space back up. So much room for activities!

Not pictured: Tons of old dead paint that was disposed of, lots of old stuff on the recycling and dead project shelves that was tossed, and of course tons of piles of dust swept up.

Have you ever needed to cut a circle? Turns out you can't just freehand that. If you want to cut a circle you need a.... Circle Jig! This handy little thing straps onto a standard router. You stick a pin in one of the little holes for the center, strap a router to the other side and route yourself a circle.

Here's a commercial circle jig. Seems simple enough. Now what if you want this thing -Right Now-? Well then you better have a Laser Cutter and some Acrylic.

Step 1 of the design comes from measuring out the dimensions of the existing router plate. What are those curved holes for? Who knows? But they look cool right?

Starting from a base circle of diameter 1/4 in (size of the router bit) we offset another circle at some whole number of mm to mark the smallest radius we can cut. Then we offset a whole bunch of other circles in 2mm increments. Then add some horizontal lines.

We want to place the center holes at intersections of the horizontal lines and circles. It took forever. And ever. That's a lot of holes.

Then you throw that on the laser cutter and BAM! New Circle jig. Well with some post processing. The laser cutter can't inset the screw holes for attaching this thing to the router. Those were cut with... A router. How about that

As the cold weather season arrives in Atlanta, with it comes issues with our 3D printers. Specifically problems with temperatures and print stability.

Freeside is essentially a big warehouse, and our 3D printing station is setup in the large open area in the front of the space. What this means is that when it is cold in the space, this will affect the printing quality because the ambient temperature is far lower than what is optimal for thermoplastics. The cold ambient air will cause parts to rapidly cool during the middle of a print. And with materials like ABS which can shrink dramatically during cooling, this causes prints to warp, deform, and delaminate during and after printing is finished.

The print on the left is showing signs of delamination from plastic cooling mid print.

To remedy this, we built an acrylic enclosure for our LulzBot AO-100, which is our dedicated ABS printer.

We tested the proof of concept of whether an enclosure would help mitigate printing problems by sticking a big cardboard box on the LulzBot to trap heat in. We also tried pushing hot air into it using a heatshrink heat gun, which turned out to actually cause the temperatures to be too high and 3D prints suffer problems on the other end of the spectrum.

The LulzBot sitting inside the shame box.

Print affected by ambient temperature being too high.

Removing the heat source made the printer spit out great quality prints, and we then moved on to building the acrylic enclosure. There is a lot of scrap materials at Freeside, including several large sheets of 1/8" and 1/4" clear acrylic. Using the outer dimensions of the LulzBot (and adding a couple inches for safety), we drew up a quick design, and cut the acrylic on the table saw.

The acrylic panels were aligned and clamped together using scrap pieces of wood, and the acrylic was bonded using acrylic glue. We also 3D printed hinge and corner pieces that we found on Thingiverse to help add support.

Always be clamping!

Two holes were drilled into the box, one in the top for the filament to feed through, and one in the back for the power and USB cables to enter into the box. The door was affixed using 3D printed hinges, model grade cyanoacrylate which melts and bonds ABS and acrylic, and a short piece of 3mm filament used for the actual hinge.

The LulzBot looking like a piece in an art exhibit.

All together the build took less than 2 days from start to finish. We need to dial in our printer settings - we had raised the extruder temperature profiles to compensate for the cold ambient air - but things are already printing much more reliably. We were uncertain if we needed some sort of heating element, but it seems that the heat put out by the extruder and the heated bed are enough to keep the inside of the enclosure warm enough for quality printing.

The next order of business will be adding a temperature sensor and an exhaust fan for when things get too warm, but that will be a project for another day!

Interestingly enough, we actually came up with the concept for this project during a meetup about interactive art installations. The idea of eye tracking came up and we discussed what we could discover with the technology. So we started to try to figure out how to a study with the free and open-source tools available. We ended up needing:

A webcam to look at the user's eyes.

ITU Gaze Tracker to calibrate and interpret that data. (However, their website is now down, so I'm not sure how viable this is as part of the toolchain now.)

OGAMA - Open Gaze and Mouse Analysis to conduct the study, display and record the data.

A custom chin rest that we fabricated and used a mouse pad for cushion

We threw together a workstation for about $400 (the laptop + webcam were the main costs) to do the study and started collecting data -

We showed surgical residents and surgeons with over 7 years of experience a series of 30 radiograph images and asked them to rate the deformity from 0 to 3 in severity. Experts tended to lock onto areas for longer and use their peripheral vision more for diagnosis. Novices would search the image by moving their focus around more and tended to rank the deformity as less severe. Our main goal was to demonstrate that this kind of data collection can be done as a proof-of-concept cost-effectively and there's a lot to learn with it. We put together a video to further explain the setup, processes, and findings here if you'd like to learn more! -

It was a fun project despite a huge number of roadblocks and setbacks with the setups, calibration, data manipulation, Despite the challenges, we came out of it with some really interesting research that demonstrates yet again how awesome it is to have a diverse community of experts and all the tools they need in one place. Support your local hackerspace/makerspace!

A bunch of great stuff got done at the build-out yesterday. A huge thanks to everyone that came out to pitch in!

Here are some pictures to recap the projects... Randy's team hung the curtain to the workshop to create more of a barrier between the front of the house and back of the house and to control dust levels a bit more. We'll be finishing the top of the wall soon, but the hard part's already done. Karen, Donald, Tom, Violet, and James framed the doorway to the Media Lab and Bio Lab and hung the door for that area. Next step is AC!

Michelle and Mary's team cleaned out project storage and moved the shelves over so that Neils could put the flammability cabinets in that area. That allowed all of us with the help of Adam and Nathan to clean up the workshop and really tidy up. They also sorted out all of the laser cutter raw materials and cut them down to a usable size on the table saw.

For the portal clouds, JW, Nathan, and Kat rolled an awesome $1 solution for controlling the WS2812 clouds with an attiny and a programming header. The schematics and board layout are included too. We used highlowtech's guide to programming the Attiny85s with the help of an instructables for driving LEDs with them that provided some supplemental information. There was an issue with setting the fuse in the ATTiny to get the timing right that we ended up having to use avrdude to change manually. Maybe that had something to do with us using the internal clock or the ATTiny-10... Anyway, more clouds coming soon :)

Thanks again to everyone who came and I'm looking forward to the next one!